Vitamin E is one of the most popular and most often used vitamin in the US. The term vitamin E is now considered to be the generic name describing both the tocopherols and tocotrienols. Structurally, tocopherols and tocotrienols share some resemblance. However, tocopherols and tocotrienols are distinguished by their side chains. While tocopherol has a saturated tail, tocotrienol possesses an unsaturated isoprenoid side chain. Tocopherols and tocotrienols are further separated into individual compounds assigned by the Greek letter prefixes—alpha, beta, gamma and delta (α, β, δ, γ). Tocotrienols and Tocopherols are found in the normal diet such as cereal grains such as wheat barley and rye. They are also found in high level in vegetable oils such as safflower, soybean, peanut, cottonseed, linseed, sunflower, rapeseed, palm and other vegetable sources. Crude palm oil and rice bran oil contain high levels of both tocotrienols and tocopherols.
Tocotrienols are known for their hypocholesterolemic effects and have been shown to decrease the blood level of the low-density lipoprotein cholesterol and the total serum cholesterol, while increasing the ratio of the high-density lipoprotein cholesterol to the low-density lipoprotein fraction (Qureshi et al., American Journal of Clinical Nutrition, 1991: 53: 1042S-1046S; Bierenbaum M L, et al., Asia Pacific Journal of Clinical Nutrition, 1997; 6(1): 72-75). Tocotrienols have been known to be beneficial for maintaining a healthy cardiovascular system.
Carotenoids are oil soluble yellow to orange red pigments found in many plants and animals. There are generally two classes of carotenoids, carotenes and xanthophylls. Carotenes are hydrocarbon carotenoids while xanthophylls are oxygenated carotenoids. Carotenoids are a group of highly unsaturated compounds and are easily decomposed by heat, light and oxygen. The more widely known carotenes are alpha, beta and gamma carotenes and lycopene. Beta-carotene and alpha-carotene are precursors of vitamin A and have been shown to inhibit tumor growth (Giovannucci E, et al., Am. J. Clin Nutr., Vol. 7294; 990-997, 2000; Murakoshi, M, et al. Cancer Research, 52; 6583-6587, 1992.). Carotenoids are present in most fruits, vegetables and numerous vegetable oils. Of the vegetable oils that are widely consumed, palm oil contains the highest known concentration of naturally derived carotenoids.
Phytosterols (including plant sterols and stanols) are natural components of edible vegetable oils such as palm oil, soy bean oil, sunflower seed oil and, as such are natural constituents of the human diet. These plant lipid-like compounds are present at low levels in grains, fruits and vegetables. There are approximately 250 different sterols and related compounds in plant and marine materials with the most common ones beta-sitosterol, stigmasterol, and campesterol.
A large body of scientific research dating back to the 1950s has documented the ability of phytosterols to block the absorption of cholesterol and reduce blood cholesterol levels. Because cholesterol and phytosterol molecules are similar, the human body can't tell the difference. Phytosterols compete with cholesterol for absorption in the small intestine. However, phytosterols themselves are not absorbed by the human body.
Historically, extraction and purification of tocotrienols/tocopherols (hereinafter referred to as tocols), carotenoids and sterols has been incomplete, low yield (not economically feasible) and involved intensive capital investment. For example, carotenoids have been extracted from crude palm oil but the tocols and sterols are typically lost during the extraction process. Like wise, carotenoids are lost during the extraction of tocols or sterols from oils. Known processes used are solvent extraction, solvent fractionation, ion exchange resin treatment and chromatography method. Most of these commercial production methods are not successful or economically attractive with low yield and substantial degradation of compounds with alteration of the natural ratio of the various isomers of tocotrienols and carotenoids after separation and purification. In addition, the chromatographic method employs the use of organic solvents, which are known to be carcinogenic.
This present invention provides a novel and efficient method for the extraction and purification of tocotrienols/tocopherols, carotenoids and sterols from oils that is simple, cost efficient with high yield as well as retaining the natural composition and ratio of the natural tocotrienols/tocopherols, carotenoids and sterols as found in the starting oils. The tocols and carotenoids concentrate are produced without the use of harmful organic solvents such as hexane, heptane or etc.